axmol/extensions/Particle3D/ParticleUniverse/ParticleEmitters/CCPUParticle3DMeshSurfaceEmitter.cpp

/****************************************************************************
 Copyright (c) 2015 Chukong Technologies Inc.
 
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 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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#include "CCPUParticle3DMeshSurfaceEmitter.h"
#include "extensions/Particle3D/ParticleUniverse/CCPUParticleSystem3D.h"
#include "extensions/Particle3D/ParticleUniverse/CCPUParticle3DUtil.h"

NS_CC_BEGIN
// Constants
const Vec3 PUParticle3DMeshSurfaceEmitter::DEFAULT_SCALE(1, 1, 1);
const MeshInfo::MeshSurfaceDistribution PUParticle3DMeshSurfaceEmitter::DEFAULT_DISTRIBUTION = MeshInfo::MSD_HOMOGENEOUS;

//-----------------------------------------------------------------------
inline void PUTriangle::calculateSquareSurface (void)
{
    /* Calculating the surface of a triangle with the following algorithm:
        v1 = Vector3(x1, y1, z1)
        v2 = Vector3(x2, y2, z2)
        v3 = Vector3(x3, y3, z3)
        a = sqrt ((x1-x3)*(x1-x3) + (y1-y3)*(y1-y3) + (z1-z3)*(z1-z3))
        b = sqrt ((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1) + (z2-z1)*(z2-z1))
        c = sqrt ((x3-x2)*(x3-x2) + (y3-y2)*(y3-y2) + (z3-z2)*(z3-z2))
        p = 0.5 * (a + b + c)
        surface = sqrt (p * (p-a) * (p-b) * (p-c));
    */

    // a, b and c are the length of each triangle
    float a = sqrt (	(v1.x - v3.x) * (v1.x - v3.x) + 
                        (v1.y - v3.y) * (v1.y - v3.y) + 
                        (v1.z - v3.z) * (v1.z - v3.z));
    float b = sqrt (	(v2.x - v1.x) * (v2.x - v1.x) + 
                        (v2.y - v1.y) * (v2.y - v1.y) + 
                        (v2.z - v1.z) * (v2.z - v1.z));
    float c = sqrt (	(v3.x - v2.x) * (v3.x - v2.x) + 
                        (v3.y - v2.y) * (v3.y - v2.y) + 
                        (v3.z - v2.z) * (v3.z - v2.z));
    float p = 0.5f * (a + b + c);

    // Assign square surface of the triangle
    squareSurface = p * (p-a) * (p-b) * (p-c);
}
//-----------------------------------------------------------------------
inline void PUTriangle::calculateSurfaceNormal (void)
{
    /* Calculating the surface normal of a triangle with the following algorithm:
        v1 = Vector3(x1, y1, z1)
        v2 = Vector3(x2, y2, z2)
        v3 = Vector3(x3, y3, z3)
        n = (v2-v1)x(v3-v1), where the 'x' is the cross product
    */
    Vec3::cross(v2-v1, v3-v1, &surfaceNormal);
    surfaceNormal.normalize();
}
//-----------------------------------------------------------------------
inline void PUTriangle::calculateEdgeNormals (void)
{
    Vec3::cross(v1, v2, &en1);
    en1.normalize();
    Vec3::cross(v2, v3, &en2);
    en2.normalize();
    Vec3::cross(v3, v1, &en3);
    en3.normalize();
}
//-----------------------------------------------------------------------
const Vec3 PUTriangle::getRandomTrianglePosition (void)
{
    // Use barycentric coordinates. Let A, B, C be the three vertices of the triangle. Any point P inside can 
    // be expressed uniquely as P = aA + bB + cC, where a+b+c=1 and a,b,c are each >= 0.
    // Knowing a and b permits you to calculate c=1-a-b.
    // So if you can generate two random numbers a and b, each in [0,1], such that their sum <=1, you've got a 
    // random point in your triangle. Generate random a and b independently and uniformly in [0,1] 
    // If a+b>1, replace a by 1-a, b by 1-b. Let c=1-a-b. Then aA + bB + cC is uniformly distributed 
    // in triangle ABC: the reflection step a=1-a; b=1-b gives a point (a,b) uniformly distributed in the 
    // triangle (0,0)(1,0)(0,1), which is then mapped affinely to ABC. Now you have barycentric coordinates 
    // a,b,c. Compute your point P = aA + bB + cC.
    float a = CCRANDOM_0_1();
    float b = CCRANDOM_0_1();
    if (a + b > 1)
    {
        a = 1 - a;
        b = 1 - b;
    }
    float c = 1 - a - b;
    return a * v1 + b * v2 + c * v3;
}
//-----------------------------------------------------------------------
const PUTriangle::PositionAndNormal PUTriangle::getRandomEdgePositionAndNormal (void)
{
    float mult = CCRANDOM_0_1();
    float randomVal = CCRANDOM_0_1() * 3.0f;
    PositionAndNormal pAndN;
    pAndN.position = Vec3::ZERO;
    pAndN.normal = Vec3::ZERO;
    if (randomVal < 1)
    {
        pAndN.position = Vec3(	v2.x + mult*(v1.x - v2.x),
                                        v2.y + mult*(v1.y - v2.y),
                                        v2.z + mult*(v1.z - v2.z));
        pAndN.normal = en1;
    }
    else
    {
        if (randomVal < 2)
        {
            pAndN.position = Vec3(	v3.x + mult*(v2.x - v3.x),
                                            v3.y + mult*(v2.y - v3.y),
                                            v3.z + mult*(v2.z - v3.z));
            pAndN.normal = en2;
        }
        else
        {
    
            pAndN.position = Vec3(	v1.x + mult*(v3.x - v1.x),
                                            v1.y + mult*(v3.y - v1.y),
                                            v1.z + mult*(v3.z - v1.z));
            pAndN.normal = en3;
        }
    }

    return pAndN;
}
//-----------------------------------------------------------------------
const PUTriangle::PositionAndNormal PUTriangle::getRandomVertexAndNormal (void)
{
    float randomVal = CCRANDOM_0_1() * 3.0f;
    PositionAndNormal pAndN;
    pAndN.position = Vec3::ZERO;
    pAndN.normal = Vec3::ZERO;

    if (randomVal < 1)
    {
        pAndN.position = v1;
        pAndN.normal = vn1;
    }
    else
    {
        if (randomVal < 2)
        {
            pAndN.position = v2;
            pAndN.normal = vn2;
        }
        else
        {
            pAndN.position = v3;
            pAndN.normal = vn3;
        }
    }

    return pAndN;
}
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
MeshInfo::MeshInfo (const std::string& meshName, 
    MeshSurfaceDistribution distribution,
    const Quaternion& orientation,
    const Vec3& scale) : 
    mDistribution(distribution)
{
    //Ogre::MeshPtr mesh = Ogre::MeshManager::getSingleton().load(meshName, Ogre::ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);
    //getMeshInformation(mesh, Vec3::ZERO, orientation, scale);
}
//-----------------------------------------------------------------------
MeshInfo::~MeshInfo (void)
{
    _triangles.clear();
}
//-----------------------------------------------------------------------
inline float MeshInfo::getGaussianRandom (float high, float cutoff)
{
    float x1 = 0;
    float x2 = 0;
    float w = 0;
    float y1 = 0;

    unsigned int max = 0;
    do
    {
        x1 = CCRANDOM_0_1();
        x2 = CCRANDOM_0_1();
        w = x1 * x1 + x2 * x2;

        // Prevent infinite loop
        if (w >= 1.0f && max > 4 )
            w = x1;
        
    } while (w >= 1.0f);
    
    w = sqrt((-2.0f * ::log(w)) / w);
    y1 = abs(x1 * w);
    y1 = y1 > cutoff ? cutoff : y1;
    y1 *= high / cutoff;
    return y1;
}

//-----------------------------------------------------------------------
const PUTriangle& MeshInfo::getTriangle (size_t triangleIndex)
{
    return _triangles[triangleIndex];
}

//-----------------------------------------------------------------------
const size_t MeshInfo::getRandomTriangleIndex (void)
{
    size_t index;
    if (mDistribution == MSD_HOMOGENEOUS || mDistribution == MSD_HETEROGENEOUS_1)
    {
        index = (size_t)getGaussianRandom((float)_triangles.size() - 1);
    }
    else
        index = (size_t)(CCRANDOM_0_1() * (float)(_triangles.size() - 1));

    return index;
}

//-----------------------------------------------------------------------
const PUTriangle::PositionAndNormal MeshInfo::getRandomPositionAndNormal (const size_t triangleIndex)
{
    PUTriangle triangle = getTriangle(triangleIndex);
    PUTriangle::PositionAndNormal pAndN;
    pAndN.position = Vec3::ZERO;
    pAndN.normal = Vec3::ZERO;
    if (mDistribution == MSD_HOMOGENEOUS || mDistribution == MSD_HETEROGENEOUS_1 || mDistribution == MSD_HETEROGENEOUS_2)
    {
        pAndN.position = triangle.getRandomTrianglePosition();
        pAndN.normal = triangle.surfaceNormal;
    }
    else
    {
        if (mDistribution == MSD_VERTEX)
        {
            pAndN = triangle.getRandomVertexAndNormal();
        }
        else
        {
            if (mDistribution == MSD_EDGE)
            {
                pAndN = triangle.getRandomEdgePositionAndNormal();
            }
        }
    }
    return pAndN;
}

//-----------------------------------------------------------------------
//void MeshInfo::getMeshInformation(	Ogre::MeshPtr mesh,
//									const Vec3 &position,
//									const Quaternion &orient,
//									const Vec3 &scale)
//{
//	size_t vertexCount = 0;
//	size_t indexCount = 0;
//	Vec3* vertices = 0;
//	Vec3* normals;
//	unsigned long* indices = 0;
//
//	bool added_shared = false;
//	size_t current_offset = 0;
//	size_t shared_offset = 0;
//	size_t next_offset = 0;
//	size_t index_offset = 0;
//
//	// Calculate how many vertices and indices we're going to need
//	for ( unsigned short i = 0; i < mesh->getNumSubMeshes(); ++i)
//	{
//		Ogre::SubMesh* submesh = mesh->getSubMesh( i );
//
//		// We only need to add the shared vertices once
//		if(submesh->useSharedVertices)
//		{
//			if( !added_shared )
//			{
//				vertexCount += mesh->sharedVertexData->vertexCount;
//				added_shared = true;
//			}
//		}
//		else
//		{
//			vertexCount += submesh->vertexData->vertexCount;
//		}
//
//		// Add the indices
//		indexCount += submesh->indexData->indexCount;
//	}
//
//	// Allocate space for the vertices and indices
//	vertices = new (std::nothrow) Vec3[vertexCount];
//	normals = new (std::nothrow) Vec3[vertexCount];
//	indices = new (std::nothrow) unsigned long[indexCount];
//	added_shared = false;
//
//	// Run through the submeshes again, adding the data into the arrays
//	for ( unsigned short i = 0; i < mesh->getNumSubMeshes(); ++i)
//	{
//		Ogre::SubMesh* submesh = mesh->getSubMesh(i);
//		Ogre::VertexData* vertex_data = submesh->useSharedVertices ? mesh->sharedVertexData : submesh->vertexData;
//
//		if((!submesh->useSharedVertices)||(submesh->useSharedVertices && !added_shared))
//		{
//			if(submesh->useSharedVertices)
//			{
//				added_shared = true;
//				shared_offset = current_offset;
//			}
//
//			const Ogre::VertexElement* posElem = vertex_data->vertexDeclaration->findElementBySemantic(Ogre::VES_POSITION);
//			const Ogre::VertexElement* normalElem = vertex_data->vertexDeclaration->findElementBySemantic(Ogre::VES_NORMAL);
//			Ogre::HardwareVertexBufferSharedPtr vbuf = vertex_data->vertexBufferBinding->getBuffer(posElem->getSource());
//			unsigned char* vertex = static_cast<unsigned char*>(vbuf->lock(Ogre::HardwareBuffer::HBL_READ_ONLY));
//			float* pReal;
//
//			for( size_t j = 0; j < vertex_data->vertexCount; ++j, vertex += vbuf->getVertexSize())
//			{
//				posElem->baseVertexPointerToElement(vertex, &pReal);
//				Vec3 pt(pReal[0], pReal[1], pReal[2]);
//				vertices[current_offset + j] = (orient * (pt * scale)) + position;
//
//				normalElem->baseVertexPointerToElement(vertex, &pReal);
//				Vec3 nt(pReal[0], pReal[1], pReal[2]);
//				normals[current_offset + j] = nt;
//			}
//      
//			vbuf->unlock();
//			next_offset += vertex_data->vertexCount;
//		}
//
//		Ogre::IndexData* index_data = submesh->indexData;
//		size_t numTris = index_data->indexCount / 3;
//		Ogre::HardwareIndexBufferSharedPtr ibuf = index_data->indexBuffer;
//    	bool use32bitindexes = (ibuf->getType() == Ogre::HardwareIndexBuffer::IT_32BIT);
//		unsigned long*  pLong = static_cast<unsigned long*>(ibuf->lock(Ogre::HardwareBuffer::HBL_READ_ONLY));
//		unsigned short* pShort = reinterpret_cast<unsigned short*>(pLong);
//		size_t offset = (submesh->useSharedVertices)? shared_offset : current_offset;
//
//		size_t numTrisMultThree = numTris*3;
//		if ( use32bitindexes )
//		{
//			for ( size_t k = 0; k < numTrisMultThree; ++k)
//			{
//				indices[index_offset++] = pLong[k] + static_cast<unsigned long>(offset);
//			}
//		}
//		else
//		{
//			for ( size_t k = 0; k < numTrisMultThree; ++k)
//			{
//				indices[index_offset++] = static_cast<unsigned long>(pShort[k]) + static_cast<unsigned long>(offset);
//			}
//		}
//
//		ibuf->unlock();
//		current_offset = next_offset;
//	}
//
//	// Create triangles from the retrieved data
//	for (size_t k = 0; k < indexCount-1; k+=3)
//	{
//		Triangle t;
//		t.v1 = vertices [indices[k]];
//		t.vn1 = normals [indices[k]];
//
//		t.v2 = vertices [indices[k+1]];
//		t.vn2 = normals [indices[k+1]];
//
//		t.v3 = vertices [indices[k+2]];
//		t.vn3 = normals [indices[k+2]];
//
//		t.calculateSquareSurface();
//		t.calculateSurfaceNormal();
//		t.calculateEdgeNormals();
//		_triangles.push_back(t);
//	}
//
//	// Delete intermediate arrays
//	delete [] indices;
//	delete [] normals;
//	delete [] vertices;
//
//	// Sort the triangle on their size, if needed (only if a gaussian random number generator
//	// function is used to perform a random lookup of a triangle)
//	if (mDistribution == MSD_HOMOGENEOUS)
//		sort(_triangles.begin(), _triangles.end(), SortDescending());
//	else
//		if (mDistribution == MSD_HETEROGENEOUS_1)
//			sort(_triangles.begin(), _triangles.end(), SortAscending());
//}
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
PUParticle3DMeshSurfaceEmitter::PUParticle3DMeshSurfaceEmitter(void) : 
    PUParticle3DEmitter(),
    _meshName(),
    _orientation(),
    _scale(DEFAULT_SCALE),
    _distribution(DEFAULT_DISTRIBUTION),
    _meshInfo(0),
    _triangleIndex(0),
    _directionSet(false)
{
}
//-----------------------------------------------------------------------
PUParticle3DMeshSurfaceEmitter::~PUParticle3DMeshSurfaceEmitter(void)
{
    if (_meshInfo)
    {
        CC_SAFE_DELETE(_meshInfo);
    }
}
//-----------------------------------------------------------------------
void PUParticle3DMeshSurfaceEmitter::prepare()
{
    // Build the data
    if (!_meshName.empty())
    {
        build();
    }
}
//-----------------------------------------------------------------------
void PUParticle3DMeshSurfaceEmitter::unPrepare()
{
    // Todo
}
//-----------------------------------------------------------------------
void PUParticle3DMeshSurfaceEmitter::initParticlePosition(PUParticle3D* particle)
{
    PUTriangle::PositionAndNormal pAndN;
    pAndN.position = Vec3::ZERO;
    pAndN.normal = Vec3::ZERO;
    _directionSet = false;

    if (_meshInfo)
    {
        getDerivedPosition();
        _triangleIndex = _meshInfo->getRandomTriangleIndex (); // Get a random triangle index
        pAndN = _meshInfo->getRandomPositionAndNormal(_triangleIndex); // Determine position and normal
        //ParticleSystem* sys = mParentTechnique->getParentSystem();
        if (_autoDirection)
        {
            if (pAndN.normal != Vec3::ZERO)
            {
                // Set position and direction of the particle
                //if (sys)
                {
                    Mat4 rotMat;
                    Mat4::createRotation(static_cast<PUParticleSystem3D *>(_particleSystem)->getDerivedOrientation(), &rotMat);
                    particle->position = _derivedPosition + rotMat * Vec3(_emitterScale.x * pAndN.position.x, _emitterScale.y * pAndN.position.y, _emitterScale.z * pAndN.position.z);
                }
                //else
                //{
                //	particle->position = _derivedPosition + _emitterScale * pAndN.position;
                //}

                // The value of the direction vector that has been set does not have a meaning
                float angle = (_dynamicAttributeHelper.calculate(_dynAngle, (static_cast<PUParticleSystem3D *>(_particleSystem))->getTimeElapsedSinceStart()));
                if (angle != 0.0f)
                {
                    //particle->direction = (pAndN.normal).randomDeviant(angle, mUpVector);
                    particle->direction = PUParticle3DUtil::randomDeviant(pAndN.normal, angle, _upVector);
                }
                else
                {
                    particle->direction = pAndN.normal;
                }

                particle->originalDirection = particle->direction;
                _directionSet = true;
            }
        }
        else
        {
            // Set position of the particle
            //if (sys)
            {
                Mat4 rotMat;
                Mat4::createRotation(static_cast<PUParticleSystem3D *>(_particleSystem)->getDerivedOrientation(), &rotMat);
                particle->position = _derivedPosition + rotMat * Vec3(_emitterScale.x * pAndN.position.x, _emitterScale.y * pAndN.position.y, _emitterScale.z * pAndN.position.z);
            }
            //else
            //{
            //	particle->position = mDerivedPosition + _mEmitterScale * pAndN.position;
            //}
        }
    
        particle->originalPosition = particle->position;
    }
}
//-----------------------------------------------------------------------
unsigned short PUParticle3DMeshSurfaceEmitter::calculateRequestedParticles(float timeElapsed)
{
    if (_meshInfo)
    {
        return PUParticle3DEmitter::calculateRequestedParticles(timeElapsed);
    }

    return 0;
}
//-----------------------------------------------------------------------
void PUParticle3DMeshSurfaceEmitter::initParticleDirection(PUParticle3D* particle)
{
    // Only determine direction if it hasn't been calculated yet
    if (!_directionSet)
    {
        PUParticle3DEmitter::initParticleDirection(particle);
    }
}
//-----------------------------------------------------------------------
const std::string& PUParticle3DMeshSurfaceEmitter::getMeshName(void) const
{
    return _meshName;
}
//-----------------------------------------------------------------------
void PUParticle3DMeshSurfaceEmitter::setMeshName(const std::string& meshName, bool doBuild)
{
    _meshName = meshName;

    // If needed, build the data needed for emitting particles
    if (doBuild)
    {
        build();
    }
}
//-----------------------------------------------------------------------
const MeshInfo::MeshSurfaceDistribution PUParticle3DMeshSurfaceEmitter::getDistribution (void) const
{
    return _distribution;
}
//-----------------------------------------------------------------------
void PUParticle3DMeshSurfaceEmitter::setDistribution(MeshInfo::MeshSurfaceDistribution distribution)
{
    _distribution = distribution;
}
//-----------------------------------------------------------------------
const Vec3& PUParticle3DMeshSurfaceEmitter::getScale (void) const
{
    return _scale;
}
//-----------------------------------------------------------------------
void PUParticle3DMeshSurfaceEmitter::setScale (const Vec3& scale)
{
    _scale = scale;
}
//-----------------------------------------------------------------------
void PUParticle3DMeshSurfaceEmitter::build(void)
{
    // Delete the mesh info if already existing
    if (_meshInfo)
    {
        CC_SAFE_DELETE(_meshInfo);
    }

    // Generate meshinfo.
    _meshInfo = new (std::nothrow) MeshInfo(_meshName, _distribution, _orientation, _scale);
}

PUParticle3DMeshSurfaceEmitter* PUParticle3DMeshSurfaceEmitter::create()
{
    auto pe = new (std::nothrow) PUParticle3DMeshSurfaceEmitter();
    pe->autorelease();
    return pe;
}

NS_CC_END